Concrete breaking machine



NW. 23, 1943. w. v. CORNETT 2,335,172

CONCRETE BREAKING MACHINE Filed Aug. 20, 1942 3 Sheets-Sheetl mvmmn WHLTER \LEURNETT daumvw ATTORNEYS 1943- w. v; CORNETT CONCRETE BREAKING MACHINE 3 Sheets-Sheet 2 i iled Au 20 194,2

I WH L'IQ'ER' V. Una/v5 TT ATTORNEYS 3 Sheets-Sheet 3 w om W. V. CORNETT CONCRETE BREAKING MACHINE Filed Aug. 20, 1942 Nov. 23, 1943.

INVENTOR. WHLTER V. BURNETT BY 5 ATTORNEY thereby permitting the boom Patented Nov. 23, 1943 UNITED STATES PATENT OFFICE 2,335,172 concur-rm panama momma Walter V. Oornett, Brooklyn, N. Y. Application August 20, um, Serial No. 455,531 10 Claims. (Cl. ass-1a) This invention relates to improvements in concrete breaking machines, and has for a principal object the provision, in a concrete breaking machine, of a vertical boom for supporting the breaker mechanism and tool; the provision of means under control of the operator, for urging said boom in either direction about its vertical axis; the further provision oi a brake drum on said boom and a brake band normally engaging said drum and holding said boom against movement; and the provision of means, under control of the operator, for letting the brake and to move in the direction selected.

Another object of the invention is the provision of a chassis, a vertical boom on said chassis, brake means partly on said boom and partly on said chassis for holding said boom against movement, a compressed air cylinder having a piston rod, connections between the pistonrod and said boom for transmitting the urge of said piston to said boom, and means under control of the operator for delivering air toeither endof said cylinder in accordance with the desired direction of movement of the boom when the latter is released, and means under control of the operator for releasing said brake means and permitting said boom to move in the direction selected.

A further object of the invention is the provision of a chassis having steerable front wheels, rear wheels connected to a differential, an air motor, and a transmission between said motor and said differential, a steering column, a boom on said chassis, an air hammer supported thereby, a seat for the operator, and a plurality of controls supported on said steering column, and all being at the operator's finger-tips, said controls constituting a control for the supply of air to said motor, a second control for the supply of air to the said chamber, and a third control for supplying air to the boom control in accordance with the direction in which it is desired that said boom be urged.

Other oblects and advantages of the invention will be apparent to those skilled in the art.

Referring to the drawings- Figure 1 is a side elevation of my new and im-- proved concrete breaking machine;

Figure 2 is a plan view of-the machine shown inFigin'el:

Figure 3 is a fragmentary view, partly in section, taken along the line 3-3 of Figure 1;

Figure 4 is a plan view with the boom removed and showing the apparatus for urging the boom shaft in either direction. This view is taken along the line 4-4 of Figure 5;

Figure 5 is an elevation, partly in section, taken along the line 5-5 of Figure 4;

Figure 6" is a sectional elevation showing the boom control, as seen along the line 6-6 of Figure 5;

Figure 7 is a perspective view of the boom king pin; and

Figure 8 is a side elevation of a modified form of the concrete breaking machine.

Referring now to the drawings, the chassis in is provided with a front axle ll carrying wheels I! and i3 and a rear axle ll carrying wheels l5 and II. The rear axle includes a differential l1 and a propeller shaft extends therefrom within the housing I. to a tion is. The transmission is directly connected to an air motor 20 and air feed lines 2] and II are connected to a source of air through a control valve 22. The control valve 22 has a rod 23 connected thereto forming an extension or the valve stem thereof, and av lever 2| connected to the upper end thereof is provided for controlling the air delivered to the motor 20.

By means of the gear shift lever 25, which may have the usual three speeds forward and one reverse, the movement or the device may be con trolled in either direction. The front wheels I! and I3 are connected to the steering gear 26 in any suitable manner so that steering of the device may be effected.

The source of air may be a flexible hose 2! leading from an air supply and connected to the pipe 23 carried on the chassis. Positioned at the rear end of the chassis and having its vertical axis cutting the axis of the rear axle I4, is a vertical boom 29.

A bearing plate 30 is secured to the chassis Hi (Figures 5 and 6), and a king pin 3| extends through a hole formed therein. Bearing onthe bearing plate is a bearing plate washer 32, which also has a hole formed thereinthrough which the king pin 3| extends.

Bearing on the bearing plate washer 32 is the tum-table boom plate 33. The boom plate 33 has fixed thereto, in concentric relation with the king pin, a brake drum 34 and surrounding the brake drum is a brake band 35 carrying brake lining 33.

The upper end of the king pin 3| has fixed thereto a locking arm 31 (see also Figure 7, which is a perspective view of the king pin).

The boom 29 may be of any suitable construction and may be secured to the tum-table boom plate by means of brackets 38 and 39 which are secured to the plate by means of bolts 40. A boom axis pin 4| passes through a hole in the boom 29 and through corresponding holes in the brackets 36 and 38, and thereby pivotally supports the boom 29 and permits the boom to be folded down, as will hereinafter be described.

The king pin 3| is threaded at 42 and a nut 43 engaging the threads 42 secures the king pin in position.

The brake band 35 has extending ears 44, 44 and a screw 45 is provided for adjusting the brake band. The brake pin 68 is associated with the ear 44. A foot-pedal 46 is mounted on a lever 41 which is plvotally connected to a bracket 48 on the chassis.

A link 49 has one end connected to the pedal and the other to the brake-band ear 44, and is provided for causing the brake band to grip the brake drum 34. While the brake band is gripping the brake drum, air may be supplied to either end of the cylinder 60 for urging the boom in a wanted direction, following which the brake may be momentarily released, permitting the boom to rotate on its support (the bearing plate 30 and the bearing plate washer 32).

The rear brace 50 has its lower end secured to the chassis by means of bolts and its upper end 52 has a bearing hole formed therein for the stud shaft 53. Likewise, the side brace 54, which is shown broken away, extends from the upper end of the boom down to the chassis to one side of the boom, and has its upper end carrying a bearing for the stud shaft 53. A second. side brace 55 is also provided on the other side of the boom, as viewed in Figure 5.

By this construction the boom may be rotated on two pivots, the king pin shaft 3| forming one pivot and the stud shaft 53 forming the other pivot.

The king pin shaft has a tapered portion 56 upon which is mounted a bell crank 51, a suitable key 58 being provided for preventing the bell crank from turning independently of the shaft. A nut 59 engaging the threads 59 secures the bell crank 51 in position thereon.

An air cylinder 60 is pivotally mounted on the chassis at 60 below the floor 6| thereof. Mounted in the cylinder 60 is a piston rod 62 which is connected to a double-acting piston within the cylinder 60.

The outer end of the piston rod 62 is yoked, the yoke being designated by the numeral 63, and a bolt 64 passes through holes in the yoke with a hole in the bell crank 51 therebetween. A suitable stufling box 65 prevents air from leaking around the piston rod 62.

An air pipe 66 has one end connected to a port at. one end of the cylinder 60 (Figured), and a pipe 61 has one end connected to a port at the opposite end of the cylinder 60. A pipe 68 has one end interconnected with the air pipe 28,.

A valve 69 (Figure 5) is mounted on the steering column 26, and the pipes 66, 61 and 68 are connected to this valve in such a manner that when the valve lever is thrown in one direction, air isadmitted to one end of the cylinder 60; and when the lever is thrown in the opposite direction, air is admitted to the opposite end of the cylinder 60. Assuming that air is supplied to the front end of the cylinder 60, as viewed in Figure 4, this air wouldtend to urge the piston toward the left, as viewed in Figure 4, and to thereby tend to urge the bell crank 51 in a clockwise direction. However, due to the fact that the operator depresses the brake pedal and causes the brake band 35 to tightly embrace the brake drum 34, the boom cannot move.

Now, to control the movement of the boom. the operator throws the lever 10 in a direction to supply air to the cylinder 60, which air will urge the bell crank 51 (and the boom connected thereto) in a wanted direction. The boom .is subjected to the urge, but cannot move until the brake 36 is released. Therefore, the operator applies the brake and applies air to the air-cylinder prior to the time that he wants the boom to move. Then when he is ready for the boom to move, he releases the brake and thereby permits the air-cylinder, through the medium of its piston and the bell crank, to swing the boom in the desired direction.

This method of control is very effective, for example, in connection with work wherein along area of pavement or the like of a given width is to be broken, the operator may start with the boom, swing to its extreme movement in one direction and may supply air to the cylinder urging the boom toward its other extreme position. With the urge continuously on the boom, he may allow the boom to gradually swing around to its other extreme position by releasing the brake for little increments of motion of the boom (for example, between strokes of the hammer), and thereby effect continuous feed of the hammer across the work in an arcuate path.

The operator may move the device forward by means of the air motor and then start another arcuate path in the opposite direction. Air may then be supplied to the opposite end of the cylinder, so as to place an urgeon the boom in the opposite direction and the operator may release the brake for small increments of movement between strokes of the hammer until the boom swings the hammer to its other extreme position. By repeating this process, long areas of concrete or the like may be broken.

The brake band may, if desired, be provided with spring means for causing the brakeband to firmly grip and brake the brake drum at all times except when released by depressing the brake pedal.

The boom may have a horizontal arm 1| projecting' therefrom and rigidly secured thereto by means of abrace 12. Suitable hangers for the hammer, one of which is designated by the numeral 13, may be secured on opposite sides of the arm 1|, and a pin 14 extending therethrough forms a pivotal support for the air hammer cylinder 15.

The air hammer has a piston rod 16 extendin from the cylinder and any suitable tool 11 may be mounted on the lower end thereof. Within the cylinder 15 is a double-acting piston, and air may be supplied to the upper end of the cylinder through a fitting 18, or to the lower end of the cylinder through a fitting 19, from a, suitable hammer control valve 80 via the flexible pipes 8| and 82. The hammer control valve 60 has a lever 89 extending therefrom by means of which the operator may control the hammer.

A flange 83 at the lower end of the cylinder 15, has a hole formed therein which is engaged by the L-shaped portion 85 of the steadying arms 84. The other L-shaped portion of the spacing member is designated by the numeral 86 and engiafigs a hole formed in the steadying arm bracke Referring to Figure 2, it will be seen that the two steadying arms 84 engage the flange 83 and of the invention as set forth in the following two sides of the cylinder 15, and engage the steadying; arm bracket 81 at points well spaced apart from each other. Therefore, the cylinder 15 is, by this arrangement, held against swinging movement toward and away from the boom, and also held against any tendency for this cylinder to rotate on its axis.

A seat 90, for the operator is mounted on a somewhat flexible support 9| and is so positioned on the frame N) that the operator has all of the controls herein described at his fingertips, Also the seat is positioned near the rear end of the machine so that the operator has a good clear view of the pavement or other material being operated upon.

The chassis maybe provided with a yoked upright 9| which forms a support for the boom un-' der conditions now to be described.

When the breaking operations have been completed, and it is desired to move the machine to another site, the boom, the hammer cylinder, and the hammer carried thereby, may be folded down by releasing the upper stud shaft 53 from the brace rods 54 and 55. This may easily be done by removing the bolts securing the said braces to the chassis, following which the boom may be swung on the pivot pin 4| to the position shown in dot-dash lines inFigures 1 and 5, or in the modification shown in Figure 8.

The steadying arms 84 are removed prior to this operation, and the steadying arm bracket 81 is also removed. A projection 92, secured to the lower end of the boom, for example by means of bolts 93, is provided for engaging the hammer rod 15a when the boom is folded down onto a removable rest Bib. In other words, the yoked upright 92 engages and holds the boom 29 steady,

and the projection 92a engages and cradles the piston rod 16. I

A modified form of the invention is shown in Figure 8, wherein the chassis lll' corresponds to the chassis in shown in Figure 1, and the arrangement of the breaking mechanism mounted on the chassis i is identical with the breaking mechanism carried on the'chassis It) in Figures 1 to 6. Like parts of the breaking mechanism bear the same numerals in all of the figures of the drawings. The boom 29 in Figure 8 is supported in the same manner and carries a brake drum 34 which is surrounded by a brake band 35, and this brake controls the swinging'of the boom and the parts carried thereon about a vertical axis, the lower end of which lies within the king pin 3!, and the upper end of which lies in the stud shaft 53 at the top of said boom.

The only difference between Figure 8 and Fi ure 1 is the difference in the means for propelling the device along the roadway. In Figures 1 to 5, inclusive, the device is propelled along the roadway by means of an air motor 20 which is connected to the transmission Hi. In the modification shown in Figure 8, the transmission (not shown) is below the cab 94 with the gear shift .lever in the usual position withrespect to the steering wheel 95. The usual internal combustion engine or motor (not shown) is positioned under the hood 98, and the usual radiator 91 is connected thereto for cooling the internal combustion engine.

Although I have herein shown and described a preferred form of the invention-andmodiflcation 1 thereof, it is obvious that many minor changes may be made in the arrangements herein shown {and described without departing rrom the spirit claims.

What is claimed is:

1. In a device of the character described, a chassis, a boom vertically mounted on said chassis adjacent to one end thereof, said boom having a lower pivotal shaft mounted on said chassis, bracing means angular with respect to said chassis and joining at their apexes to form a bearing, a stub shaft at the upper end of said boom means associated with said boom for preventing.

the latter from swinging about its axis and adapted to be released to permit said boom to swing on its axis.

3. In a device of the character described, a chassis, a boom on said chassis adjacent one end thereof, shaft means for said boom having portions extending below and above the extremities of said boom on the vertical axis thereof, spaced bearing means carried on said chassis and engaging said shaft means, crank means keyed to said shaft means, a piston rod pivotally connected to said crank means, a piston secured to said rod. a double-acting cylinder carrying said piston, and means for supplying air to either end of said cylinder for causing said boom to swing in a wanted direction about its vertical axis.

4. In a device of the character described, a chassis, a boom on said chassis adjacent one end thereof, shaft means for said boom having portions extending below and above the extremities of said boom on the vertical axis thereof, spaced said cylinder for causing said boom to swing in a wanted direction about its vertical axis, and brake means associated with said boom and adapted under control of the operator to prevent said boom from moving about its axis.

5. In a device of the character described, a

chassis, a shaft vertically journalled on said chassis adjacent to one end thereof, a brake drum secured to said shaft, a brake band embracing said drum, pedal means for causing said brake band to grip said drum, crank means keyed to said shaft, a cylinder pivotally supported on said chassis, a piston reciprocably carried in said cylinder, a piston rod extending therefrom and pivotally connected to said crank means, air ports at each end of said cylinder, and means for supplying air to either ofsaid ports, after said brake drum is engaged by said brake band for causing said piston rod to urge said 'shaft in a wanted direction about its axis, whereby an operator may release said brake means at the moment said movement is wanted.

6. In a deviceof the character described, a I

assure chassis, a bearing plate mounted on said chassis adjacent to one end thereof, a tum-table plate supported thereby, a kingpin extending through said tum-table plate and journaled in said bearing plate, a pair of spaced brackets secured] to said turn-table plate, an axis pin carried by brackets parallel to and in spaced relation with said turn-table plate, and a boom pivotally supported on said pin, said boom being'normaliy held vertical and adapted to be moved to a position out of the vertical plane about said pin as an axis.

8. A device according to claim 7, in which a bearing plate washer is positioned'between said bearing plate and said turn-table plate, and in which a brake drum is carried by said turn-table plate and embraced by a brake band.

9. A device according to claim '7, wherein a plurality of angular bracing members join to form an apex, a Journal being formed in said apex, and in which the upper end or said boom carries a stub shaft positioned in said Journal, said bracing members adapted to be removed when it is desired to move said boom to said position out of the vertical plane 10. A device according to claim 7, wherein said king pin has secured thereto a bell crank, an air cylinder pivotally mounted on said frame, a

piston in said cylinder, a piston rod connected 20 to rotat? on its vertical axis.

/ WALTER v. CORNET'I. 

